Submersible electric pump



' Jan. 27, I970 A. BLUM SUBMERSIBLE ELECTRIC PUMP Filed Feb. 27, 1968 /NVENTOR ALBERT BLUM BY i A TTORNEY United States Patent 3,491,695 SUBMERSIBLE ELECTRIC PUMP Albert Blum, Scheiderhohe, Siegkreis, Bezirk Cologne, Germany Filed Feb. 27, 1968, Ser. No. 708,567 Int. Cl. F04b 49/02; F04d 17/00; H02k /10 US. Cl. 103-25 7 Claims ABSTRACT OF THE DISCLOSURE This invention is essentially concerned with submersible electric pumps wherein a motor shaft extending to an impeller passes through a liquid sealant chamber, and electrode means in the sealant chamber indicates the degree of penetration into the sealant chamber of material being pumped.

BACKGROUND OF THE INVENTION While there have been various pump constructions of this general type employing a sealant chamber, say containing oil, and an indicating circuit connected to electrodes immersed in the sealant oil, such devices have not been entirely satisfactory.

For example, such prior devices include a pair of series connected signal lights, one of which is illuminated during normal function of the unit, the other becoming illuminated if the fluid being pumped penetrates the oil chamber. In this construction one signal light is connected to one terminal of the motor voltage source and the other signal light is connected to the pump housing ground return circuit, while an electrode is connected to a transverse circuit between the signal lights. Such circuitry employs four or five conductors, three conductors being required as power leads, an additional conductor as ground, and still another conductor as an electrode leadin wire. In this prior construction there is a distinct possibility the pump housing may become electrically connected to the voltage supply source, effecting substantial damage to the parts and endangering operators.

SUMMARY According, it is an important object of the present invention to provide a submersible electrical pump which overcomes the above-mentioned short-comings and difficulties, wherein commercial lead-in cables having a standard number of leads may be employed.

It is still another object of the present invention to provide an electric submersible pump having the advantageous characteristics mentioned in the preceding paragraph, wherein an isolating transformer may be employed with its secondary connected between an electrode and the pump housing, which the primary winding of the transformer is connected between signal means and a voltage supply source to galvanically entirely isolate the pump housing from the supply voltage, and wherein only a single additional conductor is required for feeding the transformer primary, so that conventional lead-in cables may be employed.

Other objects of the present invention will become apparent upon reading the following specification and referring to the accompanying drawings, which form a material part of this disclosure.

The invention accordingly consists in the features of construction, combinations of elements, and arrangements of parts, which will be exemplified in the construction hereinafter described, and of which the scope will be indicated by the appended claims.

Patented Jan. 27, 1970 BRIEF DESCRIPTION OF THE DRAWING The drawing in the instant application is a diagrammatic representation of a submersible electrical pump of the present invention including the supply and indicating circuitry.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now more particularly to the drawing, a pump housing is generally designated 1, which may be disposed in generally upright condition, as illustrated, and submerged into the liquid being pumped, such as sewage, or the like. The housing 1 may of a metal, electrically conductive structure, and is divided, as by a transverse partitional wall 1a, into a motor chamber 2 and impeller chamber 3, the former being superposed over the latter. A motor 4 is diagrammatically represented as being mounted in the motor chamber 2, while an im peller 5 is shown as mounted in the impeller chamber 3.

Interposed between the motor chamber 2 and impeller chamber 3 is a liquid sealant chamber 7, which contains a suitable sealant, such as oil, or the like. A drive shaft 6 extends from the motor 4 through the sealant chamber 7 and is connected in driving relation with the impeller 5. Thus, the drive shaft 6 extends through suitable shaft seals, as at 7a and 7b, on its passage through the upper and lower walls of the sealant chamber 7.

Mounted in the sealant chamber 7, immersed in the sealant liquid or oil of the sealant chamber and located in spaced relation with respect to the sealant chamber walls, is an electrode 8. The electrode 8 is connected by a conductor 8a which passes in sealed relation outwardly from the sealant chamber, for a purpose appearing presently. If desired, an additional electrode may be mounted in the sealant chamber 7; or as in the illustrated embodiment, the material of the sealant chamber may be employed as an electrode and electrically connected, as by the partition 1a to the housing 1, so that the electrode 8 and material of the sealant chamber 7 combine to define cooperating electrodes.

Also mounted in the housing 1, say above the motor 4 in the motor chamber 2, is a transformer 9 having a primary coil 91 and a secondary coil 92. A lead-in cable is generally designated 10, being diagrammatically represented by a dashed line, and may be a five-wire cable in the instant embodiment. The cable wires are respectively designated 15, 16, 17, 20 and 21. The lead-in wires 15, 16 and 17 are respectively connected to the phases of a threephase motor 4. The lead-in conductor 21 is connected between ground and the housing 1 to ground the latter.

Further, it will be seen that the secondary winding 92 of transformer 9 is connected on one side by the conductor 8a to the electrode 8, and is connected on its other side to the ground wire 21, which is also connected to the housing 1. The primary coil 91 of the transformer 9 is connected on one side to the supply line 15, and connected on its other side to the lead-in conductor 20.

The lead-in cable 10 may extend from the pump housing 1 to a connection box 13, which may be of any suitable construction. The connection box 13 includes an onoff switch 14 which selectively connects the three-phase motor wires 15, 16 and 17 to a source of power. The ground wire 21 may be connected by a conductor 22 to the box 13 to ground the latter.

Also provided in the box 13 may be indicating means, say including a signal 11, such as a lamp, connected on one side by a conductor 23 to one of the power supply lines 16. The lamp 23 is connected on its other side by conductor 18 to the conductor 20, which is connected to one side of the transformer primary 91. The other side of the transformer primary 91 is connected to the supply line 15, so that the lamp or signal means 11 is effectively connected across the supply lines 15 and 16. A resistor 19 of suitable value may be connected in parallel with the lamp 11. In addition, a signal means or lamp 12 may be connected between the conductor 18 and power supply line 15, so as to be in parallel with the primary coil 91. Thus, the signal means or lamp 12 is in parallel with the transformer primary and in effective series connection with the signal means or lamp 11.

It will now be appreciated that the transformer 9, being in the motor chamber 2, is elfectively protected from damage by the material being pumped, and the transformer secondary 92 is effectively isolated from the remainder of the circuitry. In normal operation, the resistance in the transformer secondary 92, as through the oil in sealant chamber 7, causes primary current to by-pass through parallel connected signal means 12, so that the later indicates a normal operating condition. Upon dielectric change in the sealant chamber 7, a resistance change is reflected to the circuit of transformer primary 91, so that the potential or voltage in conductor 18 is changed to effect energization of signal means or lamp 11 and deenergization of lamp 12. Thus, lamp 11 will indicate an abnormal condition requiring remedial procedures.

Of course, it is appreciated that only an abnormal condition signal may be used, if desired, therefore eliminating the normal operation signal and only indicating a malfunction.

From the foregoing, it is seen that the present invention provides a submersible electric pump which fully accomplishes its intended objects and is well adapted to meet practical conditions of manufacture, installation and use.

Although the present invention has been described in some detail by Way of illustration and example for purposes of clarity of understanding, it is understood that certain changes and modifications may be made within the spirit of the invention and scope of the appended claims.

What is claimed is:

1. In a submersible electric pump including an impeller chamber, an impeller in said impeller chamber, a motor chamber adjacent to said impeller chamber, a motor in said motor chamber, a liquid sealant chamber interposed between said impeller and motor chambers, and a shaft extending from said motor through said liquid sealant chamber to said impeller for driving the latter; the improvement comprising a pair of electrodes in said sealant chamber, an isolation transformer having its secondary electrically connected on one side to one of said electrodes, ground means connected to the other side of said secondary and to the other of said electrodes, the primary of said transformer being electrically connected across the supply line of said motor, and signal means electrically connected to said primary for energization upon change in resistance between said electrodes.

2. A submersible pump according to claim 1, the other electrode comprising the material of said sealant chamber.

3. A submersible pump according to claim 2, said motor, sealant and impeller chambers being electrically connected to the ground.

4. A submersible pump according to claim 1, said signal means being electrically connected in series with said primary.

5. A submersible pump according to claim 4 in combination with additional signal means electrically connected in parallel with said primary for energization under normal operating conditions, and deenergization upon energization of said first-mentioned signal means.

6. A submersible pump according to claim 5, said signal means comprising lamps.

7. A submersible pump according to claim 1, Said transformer being mounted interiorly of said motor chamber.

References Cited UNITED STATES PATENTS 2,239,270 4/1941 Jahreis 10325 3,157,128 1l/1964 Husting 103-87 3,392,983 7/1968 Hajner 27728 ROBERT M. WALKER, Primary Examiner US. Cl. X.R. 

